I provide a weather email service for people in MD. I am a storm chaser & Skywarn spotter. For daily weather tidbits follow me on Twitter: @wxmanMD.
By: cws6196 , 2:58 PM GMT on December 29, 2012
Patience ... If you want snow it will happen in a few hours, but only if you are north and west of Baltimore. Yes, I went out on a limb and got pushed off by Mother Nature... For an explanation of what happened and where I went wrong see below.
TIMING: The storm is strengthening and the snow will fall in a couple hours. Those in S MD have rain now. The precip should be over late afternoon/early evening.
ACCUMULATION: Those around Baltimore "may" see a dusting while those south will only have rain. Those north and west could see a couple inches while those along the MD/PA line could see 3 or so.
WHAT HAPPENED? The term you will hear today is "dry slot". All the right dynamics were in place late last night for a good snow storm, but then the dry slot happened. The low in the TN area was dying while a new low was forming around FL. That latter low was the one to move up the coast and give us the snow. It is moving up the coast, but it formed too slowly (late) and too far to the south. Had it formed a bit closer to the TN low and quicker it would have taken much of the energy from the dying low and adding to it's new energy. Since that did not happen it allowed for a dry slot to form in between the two lows. Therefore, overnight we saw precip in western MD and S MD, but the central part was dry. Dry slots are not easy to forecast since we can't yet determine exactly how quickly a new low will form. Have a dry slot during the period when the initial snow was to fall decreases the overall snow accumulations since it started later but will end the same time. Also, since the energy wasn't transferred the new low is weaker. In summary, this is why only a portion of MD will see snow, and less than I forecasted. I hate to be wrong, especially when it means less snow, but I was.
The next system to watch is mid next week. It's too early yet for me to comment on that system, but know that snow is possible again.
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